Supercharged fuel injection internal combustion engine



United States Patent Inventors Ortwin Peyker Rosrath-Stumpen; UdoHickmann, Langenfeld-Hardt; Wilhelm Marx, Lovenich, Germany Appl. No.744,799 Filed July 15,1968 Patented Dec. 15, 1970 AssigneeKlockner-Humboldt-Deutz Aktiengesellschafl Cologne-Deutz, GermanyPriority July 22, 1967 Germany No. 1,576,315

SUPERCHARGED F UEL INJECTION INTERNAL COMBUSTION ENGINE 4 Claims, 4Drawing Figs.

U.S.Cl 123/140 Int. Cl F02d 9/00 Field of Search 123/139,

[56] References Cited UNITED STATES PATENTS 2,214,766 9/1940 Hurstl23/139.l8 2,244,669 6/1941 Becker 123/l40.3 2,901,885 9/1959 Reggiol23/140.3 2,914,056 11/1959 Hughson et a1. 123/140 3,077,873 2/1963Parks et a1. 123/140.3 3,107,483 10/1963 Hamilton 123/140.3 3,234,9272/1966 Cramer Jr 123/140 Primary Examiner-Laurence M. GoodridgeAttorney-Walter Becker ABSTRACT: For use in connection with a fuel pumpequipped internal combustion engine, a control device which includeshydraulically operable adjusting means adapted to be connected to a fuelpump for adjusting the delivery thereof, control means associated withsaid adjusting means for controlling the hydraulic actuation thereof,and exhaust gas temperature responsive means operatively connected tosaid control means for actuating the same in response to the ascertainedexhaust gas temperature exceeding an admissible maximum value.

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" to oil reservoir charging 0!! oil under pressure Fig. 2

ail outflow of! under pressure charging oil under pressure In Vento 5each other;

SUPERCHARGED FUEL INJECTION INTERNAL COMBUSTION ENGINE The presentinvention relates to a supercharged fuel injection internal combustionengine with means for preventing overheating conditions. Devices areknown for avoiding overheating conditions caused by too low a chargingpressure or too high a temperature of the charging air. These heretoforeknown devices are, however, not fully satisfactory, inasmuch as anoverheating of the engine may also be caused by other circumstances as,for instance, by defective injection nozzles These and other objects andadvantages of the invention will appear more clearly from the followingspecification, in connection with the accompanying drawing, in which:

FIG. 1 shows a device according to the invention, in which adifferential piston and the control piston are in alignment with FIG. 2shows a device according to the invention, in which the differentialpiston and the control piston are laterally offwith a means forpreventing overheating conditions is, in con formity with the invention,characterized by adevice for controlling the quantity of theinjectedfuel in conformity with the exhaust gas temperature in such away that the latter never exceeds the maximum admissible temperature.For purposes of obtaining an additional protection of the engine againstmechanical overload, it is provided in conformity with a furtherdevelopment of the present invention to arrange in parallel to theexhaust gas temperature depending control, a control which is dependenton the pressure of the charging air so that when the charging pressureincreases to an undesired extent, the quantity of fuel is decreased insuch a way that the maximum admissible ignition pressure will not beexceeded.

The control device according to the present invention may be of anysuitable design and may operate mechanically, pneumatically, orhydraulically. The hydraulic operation is to be preferred, inasmuch asit offers the better conditions for avoiding friction losses to amaximum extent. A suggestion in this direction consists in providing acontrol valve which follows the movement of an exhaust gas temperaturefeeler, and if desired, of a charging air pressure feeler. This controlvalve controls the supply of oil under pressure to the working chamberwhich is associated with the larger actuating surface of a differentialpiston which is coupled to the delivery control element of the fuelinjection pump. The adjusting'movements of said control valvearecounteracted by the-adjusting move ments of thedifferential pistonthrough the intervention of a return device for restoring the powerbalance between the control spring and the adjusting force exerted bythe feeler upon the control valve.

Referring now to the drawing in detail which illustrates two embodimentsof the invention, according to which the control of the fuel supply tothe engine is effected in conformity with the exhaust gas temperatureand in conformity with the charging air pressure, the device of FIG. 1primarily comprises a housing I in which on the left-hand side there isguided a differential piston 2 whereas on the right-hand side adjacentthereto, there is guided a control piston 3. The device shown in FIG. 1furthermore comprises an exhaust gas temperature control member 4 whichis filled with mercury steam, and acts upon said control piston 3. Thedevice of FIG. I furthermore comprises a spring loaded diaphragm 5acting upon the control piston 3 and responsive to changes in thecharging air pressure. The reduced end of the differential piston 2protrudes from the housing 1 and serves for a positive connection withthe delivery adjusting member of the nonillustrated fuel injection pump,and more specifically only in the direction which brings about areduction in. the delivery. The differential piston .2 is by means of acontrol spring 6 held in abutment with the delivery adjusting member,whereas the spring 6 presses the control piston- 3 against the adjustingmembers 4and 5. The control piston 3 is provided with a groove 7 whichis continuously filled with oil under pressure. As will be seen from thedrawing, the groove 7 is in continuous communication with a chamber 8associated with the smaller actuating surface 2a of the differentialpiston 2. The control piston 3 is furthermore provided with a groove 9which communicates with the discharge passage 10. That portion of thecontrol piston 3 which is located between the grooves 7 and 9 is adaptedin cooperation with the control bore 11 in housing 1 and in conformitywith the movements of the feelers 4 and 5 to control the admittance ofoil under pressure from the groove 7 to the working chamber 12 of thedifferential piston 2-said chamber 12 being associated with the largeractuating surface 2b of differential piston 2-and the discharge fromchamber 12 to the discharge passage 10. The diaphragm 5 is actuated uponbythe pressure of the charged air through the opening 13 in the housingI. The supply of oil under pressure is effected through passage 15.

"The device illustratediin FIG. 1 operates in the following manner: Whenthe device occupies the position shown in the drawing, oil continuouslyflows in the direction of the arrows shown therein from the groove 7 ina throttled condition through a control bore II into the working chamber12. At the same time from the working chamber 12 oil flows in throttledcondition to the discharge passage 10. If now, for instance, the exhausttemperature increases, the control piston 3 is displaced toward the leftagainst the thrust of spring 6. As a result thereof, the oil flowinginto the chamber 12 is .throttled to a greater extent whereas the oilflowing out of the chamber 12 is throttled to a lesserdegree. In thisway, chamber 12 will be relieved, whereas the pressure in chamber 8 willincrease somewhat more. Differential piston 2 will thus move in therightward direction with regard to the drawing, thereby reducing thefuel supply to the engine. At the same time, the spring '6 is loadedfurther whereby the control piston 3 is moved back. The two pistons 2and 3 will thus adjust themselves for a new starting position which hasbeen reached as soon as a balance of forces has, been establishedbetween the spring 6 and the feeler 4. The diaphragm 5 which is underthe continuous influence of the pressure of the charging air and isunder the load of a spring 14 is intended to reduce the fuel supply whenthe charged air pressure increases. This downward control becomeseffective only from a charging air pressure determined by the strongspring 14 and in the same direction as the exhaust temperature feeler 4.

Due to the fact that the differential piston 2 and the control piston 3are arranged in axial alignment with each other and rest against eachother solely through the spring 6, a turning off movement will bepossible only in the direction in which the spring 6 is tensioned by amovement of the differential piston 2 toward the right (with regard tothe drawing).

FIG. .2 shows a device according to the invention in which thedifferential piston 16 and the control piston 17 are laterally offsetwith regard to each other, said piston 16 and 17 being coupled to eachother by a lever 18 and a spring 19. In view of this offset arrangement,both adjusting directions may be selected by a correspondingdisplacement of the pivot point of lever 18. When said pivot point islocated between the two axes of said pistons 16 and 17, a turning offdirection is obtained which is opposite to the turning off direction ofFIG. I. In all other respects, the device of FIG. 2 operates in a mannersimilar to that described in FIG. 1.

FIG. 3 shows a four-cylinder combustion engine 20. The exhaust gases ofthis machine or engine pass through a manifold 21 or gas collecting tube21 to a gas turbine 22 which drives a turbocompressor 23. The combustionair suctioned off by this compressor 23 through a filter 24 is forwardedby way of a collector conduit 25 to the machine or engine and from thecollector conduit 25 in a manner not visible in the drawing there arebranch conduits leading to each individual inlet valve. A double lever28 journaled rotatably at one end of the pump 26 has effect upon aprojecting end of the fuel quantity adjusting member 27 of the fuelinjection pump 26. The other end of the lever 28 is pivoted to engageagainst the adjusting or differential piston 2 of the arrangement orconstruction according to FIG. 1. This hydraulically or fluid operatingadjusting arrangement is at one time connected by way of conduit 29 tothe exhaust collecting conduit 21 of the combustion engine 20 andadditionally by way of conduit 30 the same adjusting arrangement isconnected to the combustion air collecting conduit 25. The pressurizedoil or fluid is supplied to the arrangement by way of the conduit 31. Assoon as the exhaust temperature of the combustion engine and/or thepressure of the combustion air in the conduit 25 exceeds a particularmaximum value, the described, hydraulically operating arrangementdifferentially adjusts the fuel quantity adjusting member 27 of the fuelinjection pump 26 by way of the double lever 28 in the sense of areduction of the injected fuel quantity, which means in a minusdirection, and particularly so far as and so long as is required untilthe exhaust temperature again is reduced to the highest permissiblevalue or somewhat below the same.

H0. 4 makes apparent the attachment of the differential adjustingarrangement according to FIG. 2 on the same combustion engine or machineas described with FIG. 3. The embodiment or arrangement according toFIG. 2 correspondingly is connected with the exhaust collecting conduit21 of the machine by way of conduit 32 and with the collecting conduit25 for the combustion air by way of the conduit 33.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular embodiments shown in the drawing, butalso comprises numerous modifications, the scope of the invention beingdetermined by the disclosure.

We claim:

1. A control device for limiting flow of fuel to an internal combustionengine to avoid overheating of said engine, in which said engineincludes a fuel pump having a delivery adjusting member to limit flow offuel from the pump, a manifold for passage of exhaust gases, and asource of charging air for combustion, said control device comprising afluid actuated member connected to said delivery adjusting member tomove said adjusting member to limit flow of fuel to said engine, acontrol valve movable to admit fluid under pressure to operate saidfluid actuated member, a temperature responsive member and a pressureresponsive member each operable independently to move said control valveto admit fluid under pressure to said fluid actuated member, saidtemperature responsive member being responsive to exhaust gastemperature in excess of a given maximum value to move said controlvalve, said pressure responsive member being responsive to pressure ofsaid charging air in excess of a given maximum value to move saidcontrol valve, said temperature responsive and pressure responsivemembers operating in parallel either separately or together to move saidcontrol valve so that either excessive exhaust gas temperature orexcessive charging air pressure will move said control valve to causemovement of said fluid actuated member and limit flow of fuel to saidengine.

2. A control device according to claim 1, in which said temperatureresponsive member and said pressure responsive member are in engagementwith said control valve, and said pressure responsive member is movablerelatively to said temperature responsive member. A

3. A control device according to claim 1,1n which said control valve isa piston valve and said temperature responsive and pressure responsivemembers are coaxial with and in engagement with said valve.

4. A control device according to claim 1, in which said control valve isa piston valve and said temperature responsive member is an expansiblemember coaxial with and in engagement with said valve, said pressureresponsive member including a diaphragm actuated member surrounding saidtempera- 0 ture responsive member and in engagement with said controlvalve.

